(a) Technical Field
The present invention relates to an inside mirror assembly of a vehicle. More particularly, the invention relates to an inside mirror assembly of a vehicle having an improved structure capable of implementing reflective surfaces of a day mode and a night mode, selectively, according to light reflectivity.
(b) Background Art
In general, an inside mirror (also called a room mirror) of a vehicle is arranged to guarantee a view to a rear passenger seat and a rear side, and is mounted on the seal at the upper side of a boundary between a driver's seat and a front passenger seat such that an angle thereof is adjustable.
The inside mirror assembly includes a housing assembled to the seal by a ball joint and a mirror glass mounted on the front side of the housing to reflect light.
Since a majority of mirror glasses has a flat reflection side of a prescribed thickness, light emitted from headlamps (especially, high beams) of following vehicles is directly reflected so that the reflected light tends to blind the driver. To prevent this, a frameless inside mirror assembly is adopted to adjust light reflectivity.
The existing frameless inside mirror assembly will now be described with reference to FIGS. 1 and 2 as follows.
As shown in FIGS. 1 and 2, a reference numeral 10 indicates a housing 10 of the mirror assembly and a reference numeral 20 indicates a prism glass.
A frameless prism glass 20 is fixed to a front opening of the housing 10, while the prism glass 20 becomes gradually thinner extending down from the upper side.
In this case, the housing 10 is mounted to adjust an angle thereof by a ball joint 12, and a lever 14 is connected to the ball joint 12 to adjust an angle of the housing 10.
The front surface of the prism glass 20 is a first reflective surface 21 implementing a night reflection mode, and a rear surface thereof is a second reflective surface 22 coated with a reflective material implementing a day reflection mode.
As shown in FIG. 2, in the day reflection mode, a rear side object and rear side light are reflected by the second reflective surface 22 of the prism glass 20 such that a driver may see the rear side object reflected from the second reflective surface 22, and simultaneously light reflected from the second reflective surface 22 enters the driver's eyes.
On the other hand, in the night reflection mode, when the lever 14 is manipulated to lower the light reflectivity and is moved downwardly about the ball joint 12 to tilt the housing 10 upward (about 3.5 degrees), the prism glass 20 is tilted at the same angle with the housing 10 and the rear side object and the rear side light are reflected from the first reflective surface 21 of the prism glass 20.
As such, the prism glass 20 is tilted to adjust a reflection angle in the night reflection mode so that the light entered from the rear side object (especially, the light of headlamps of following vehicles) is reflected by the first reflective surface 21 at a lowered reflectivity, preventing a driver's eyes from being blinded.
However, the above-described existing inside mirror assembly has drawbacks as follows:
First, when the rear side object is reflected from the first and second reflective surfaces of the prism glass when in the day reflection mode and the night reflection mode, since a condition in which a real image and a virtual image on the prism glass are overlapped arises due to a characteristic of the prism glass, a driver often recognizes the rear side object but experiences eye discomfort
Second, there is inconvenience in that a driver normally does not recognize the inside mirror assembly as having been tilted during travelling when in a day reflection mode on the day after travelling in the night reflection mode (although a driver may recognize the changed position of the housing because of the tilted housing), and often uses the inside mirror assembly by adjusting the housing. However, he/she eventually recognizes the changed position of the lever during night travelling to again adjust the housing.
To solve these drawbacks, this applicant previously filed Korean Patent Application 10-2014-0057030, that is, an “inside mirror assembly of a vehicle in which a fixed reflective plate fixed to a front opening of a housing and a tilting reflective plate disposed parallel to the rear side of the fixed reflective plate in a day reflection mode and tilted in the night reflection mode, wherein the fixed reflective plate and the tilting reflection plate are disposed before and after the housing such that the image overlapping in which a virtual image and a real image are overlapped with each other in the day reflection mode is reduced and in which a tilting trace for switching the day reflection mode into the night reflection mode and vise versa is always uniform, and in which a driver can recognize the reflection mode intuitively.”
However, as shown in FIG. 3 herein, a slot hole is adopted in a portion to which the tilting reflection plate and a tilting bracket are connected for a tilting trace, in particular, three more pivot shafts with different traces are used, and a linkage structure to which respective pivot shaft are connected is complex, resulting in play.